1. Field of the Invention
The present invention relates to a bearing device for rotary machines, such as small-sized electric motors and, more particularly, to a bearing device having a sleeve bearing for rotary machines.
2. Description of the Prior Art
A bearing device for small-sized electric motors has a sleeve bearing on a bearing support member of an end bracket, and a rotary shaft is rotatably supported through the sleeve bearing.
Such a bearing support member is double-annularly constructed, which consists of an inner annular portion and an outer annular portion as shown in U.S. Pat. No. 3,224,819, and these annular portions are joined together at the axially inside sections thereof.
The sleeve bearing is press-fitted into the inner annular portion so as to be fixed therein. A cap made of a steel plate is press-fitted around both axial end sections of the outer annular portion via a sealing adhesive coated on the cap so as to prevent oil leak from the caps. These caps thereby form inside and outside annular reservoirs, in which felt or an oil-containing fibrous material is inserted.
In a bearing device having the above-described construction, the lubricating oil contained in the felt or oil-containing fibrous material provided in the inside and outside oil reservoirs is introduced into the felt inserted in an annular cavity provided between the inner annular portion and outer annular portion, and oil feed bores provided in the inner annular portion and sleeve bearing. Ths lubricating oil is then supplied to the rotary shaft supporting portion of the inner circumferential surface of the sleeve bearing, lubricating oil being supplied therefrom to the outer surface of the rotary shaft.
A conventional bearing of the above-described construction has as mentioned above inside caps made of a steel plate separately from the end bracket and press-fitted into the outer annular portion of the bearing support member. A sealing adhesive is coated on the caps for the prevention of oil leak therefrom to thereby form an inside oil reservoir. Accordingly, such a bearing device has a large number of parts. Moreover, the press-fitting of caps and the coating of a sealing adhesive are required. This causes an increase in the number of assembling steps and manufacturing cost.